The FM50 should work, it is a 2Hp version and should have no issues with a 1.5Hp motor. The input voltage to the VFD nees to be 230VAC (or per the nameplate specifications). Check to see that you motor winding's are connected correctly and that the motor is wired for 230V. The FM50 may not be set in the proper frequency mode. This requires a complete VFD reset/reprogramming, and this is done by setting F_25 to 020 which will initialize the system to 60Hz. I would set F_2 to either 2.o or 3.o seconds, F_05 to 5 (high Torque), set F_12 to 6 (carrier frequency to 10 Khz), set F_13 to 10 for maximum torque, F_14 to 0 controlled deceleration, F_17 to 20.0%, F_18 to 150%, F_24 to 0. Automation Direct has very good tech. support, but I have not seen this model sold at their site for many years.
The wj200-015sf is available for for $283 shipped.
https://www.driveswarehouse.com/wj200-015sf-2526
The Teco 7300CV is available for for $240 shipped.
http://www.factorymation.com/CV-2002-H1
I believe the new version of the Teco N3 is the 7300CV, I do not recommend the Teco L510 as I have read a number of posts where they have had performance issues with the drive. Also the L510 does not support an external braking resistor on the 230V version, and an external braking resistor is often needed on a lathe because of the larger rotating mass. There is also the Automation Direct GS3 VFD, which I believe is a repackaged Teco N3. These mid-priced VFDs offer a number of features and can be run in sensorless vector mode which allows bettor motor control/power over a wider operating range. Sensorless vector is a motor feedback system to the VFD so it can give you more stable RPM/power control. I would not buy a VFD through eBay, nor any of the generic Chinese VFDs for this application.
In general, VFDs require some modifications to work with the lathe controls for safety features and to work properly with your E-Stop. Otherwise there is the possibility of the the lathe starting if the spindle direction was left on. There are different ways to prevent this. You always want to program the VFD so auto-restart with power failure is OFF. The WJ200 has a small power internal supply that can operate a 24VDC power relay to prevent this, there are also a few other ways to do this. I work mostly with the WJ200, they have been very reliable (I have yet to hear of one failing). The manual stinks, but I can help you with a schematic and programming parameters for the VFD. But it is important to note that VFDs do take some rewiring and programming to work properly with your lathe.